Method and apparatus for drying wet surfaces

ABSTRACT

Method and apparatus for drying wet surfaces, especially the wet surface of a photoelectric or electric copy carrier, in which elongated electrode means, having points directed toward, but out of contact with the wet surface of a carrier, and the carrier are moved relative to each other in a direction transverse to the elongation of the electrode means, while a potential difference of about 4-8 kv is applied to the carrier and the electrode means to thus produce gas ions emanating at high speed from the points of the electrode and a resulting gas-ion and air stream directed to the carrier surface which will push the liquid film off the surface during relative movement of the electrode means and the carrier.

United States Patent [191 Kohlmannsperger METHOD AND APPARATUS FOR DRYING WET SURFACES lnventor: Josef Kohlmannsperger, Munich,

Germany Assignee: Agia-Gevaert Aktiengesellschaft,

Leverkusen, Germany Filed: Feb. 6, 1973 Appl. No.2 330,046

Foreign Application Priority Data Feb. 8, 1972 Germany P 22 05 800.0

U.S. Cl. 34/1, 219/1081 Int. Cl. F26b 3/34 Field of Search 34/1; 2l9/10.8l;

References Cited UNITED STATES PATENTS 2/1941 Stephen 219/1081 6/1972 Candor et a1 34/1 3,636,637 1/1972 Keith 34/1 Primary Examiner-Carroll B. Dority, Jr. Assistant Examiner-Larry I. Schwartz Attorney-Michael S. Striker [5 7] ABSTRACT Method and apparatus for drying wet surfaces, especially the wet surface of a photoelectric or electric copy carrier, in which elongated electrode means, having points directed toward, but out of contact with the wet surface of a carrier, and the carrier are moved relative to each other in a direction transverse to the elongation of the electrode means, while a potential difference of about 4-8 kv is applied to the carrier and the electrode means to thus produce gas ions emanating at high speed from the points of the electrode and a resulting gas-ion and air stream directed to the carrier surface which will push the liquid film off the surface during relative movement of the electrode means and the carrier.

9 Claims, 3 Drawing Figures PATH- TED DU 1 m SHEET 2 BF 2 METHOD AND APPARATUS FOR DRYING WET SURFACES BACKGROUND OF THE INVENTION The present invention relates to a method and apparatus for drying wet surfaces, especially wet surfaces of photoelectric or dielectric copy carriers.

Up to now, such copy carriers have been dried by means of squeeze rolls and hot air Squeeze roll systems are relatively complicated and quite often subjected to breakdown and may also lead to a fogging of the surface to be dried, whereas hot air drying carried out at relatively high temperatures, can detrimentally affect the copy, respectively the copy carrier.

SUMMARY OF THE INVENTION It is an object of the present invention to provide for a method and apparatus for drying wet surfaces, especially wet surfaces of a copy carrier, which avoid the above-mentioned disadvantages of methods and apparatusses known in the art.

It is an additional object of the present invention to provide for a method and apparatus for drying wet surfaces, especially wet surfaces on a copy carrier, which will assure removal of a liquid film from the surface without engaging the latter and without detrimentally affecting the copy, respectively the copy carrier.

It is an additional object of the present invention to provide for an apparatus of the aforementioned kind which is simple in construction so that it may be manufactured at reasonable cost and will stand up properly under extended use.

With these and other objects in view, which will become apparent as the decription proceeds, the method according to the present invention for drying wet surfaces, especially wet surfaces of electrographic or dielectric copy carriers, mainly comprises the steps of moving an elongated combshaped electrode, having points directed toward but out of contact with the wet surface of a carrier, and the latter relative to each other in a direction transverse to the elongation of the electrode while applying a potential difference to the eletrode and the carrier to thus produce gas ions emanating at high speed from the electrode and a resulting gasion and air stream directed toward the surface which will push a liquid film on the surface off the latter during the relative movement of the electrode and the carrier.

The apparatus for carrying out the above method mainly comprises support means having a surface for supporting a copy carrier with the wet surface thereof exposed, elongated electrode means having a plurality of closely adjacent pointed elements, the points of which are closely adjacent but out of contact with the exposed wet surface of the copy carrier on the support means, the support means and the electrode means being arranged for movement with respect to each other in a direction transverse to the elongation of the electrode means, and means are provided for applying a potential difference to the electrode means and the support means and a copy carrier thereon.

The support means with the copy carrier thereon may be arranged stationarily and in this case there is preferably provided a carriage mounting the electrode means for movement in the aforementioned direction and the support means preferably also includes means for guiding the carriage during its movement relative to the support means.

The aforementioned pointed elements may be constituted by pointed teeth of a comb-shaped electrode, and this electrode may either be straight or V-shaped, located in a plane substantially parallel to the surface on the support means with the apex of the V-shaped electrode located between side edges of a carrier on the support means and arranged in such a manner that during relative movement of the elctrode and the support means with the carrier thereon, a wet film on the exposed surface will be displaced toward the side edges of the carrier.

On the other hand, the electrode means may also comprise an elongated cylinder having a plurality of pointed elements, such as pins, projecting closely arranged to each other in substantially radial direction from the peripheral surface of the cylinder and in this case the apparatus may include means for rotating the cylinder about its axis during relative movement of the electrode means and the carrier in a direction transverse to the axis.

Due to the special form and the small radii or curvature of the pointed elements of the electrode means described, the strength of the electric field on the edges and points of the electrode will be very great so that the air between the electrode and the wet surface will be ionized and the thus produced gas ions will obtain a very high speed. This will result in a gas-ion-air stream directed toward the wet surface which will, during relative movement of the electrode means and the wet surface on the copy carrier, push the liquid film on the exposed surface of the copy carrier toward the end edge of the latter to which the electrode moves, respectively, if the electrode means is V-shaped, toward the side edges of the copy carrier.

Since electrographic copying apparatus are provided with a source of high tension, which, during drying of the copy carrier, will not be needed, this source can be used for applying the potential difference to the electrode means and the copy carrier on the support means.

Instead of a single straight elongated electrode or a single V-shaped electrode, two or more such electrodes may be arranged parallel to each other to obtain an improved drying of the copy carrier and the same result will also be obtained with the above-mentioned rotatable electrode means.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however,

both as to its construction and its method of operation together with additional objects and advantages, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic perspective view of a first embodiment of an apparatus according to the present invention in which the electrode means comprise two substantially straight and parallel comb-shaped electrodes;

FIG. 2 is a schematic perspective view of a second embodiment in which the two electrodes are V-shaped; and

FIG. 3 is a schematic perspective view of a third embodiment in which the electrode is a rotatable cylindrical electrodewith rows of pointed elements thereon.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawing, and more specifically to FIG. 1 of the same, it will be seen that the apparatus according to the present invention may comprise support means 1, shown in FIG. 1 as a support plate preferably consisting of aluminum having an upper surface adapted to support thereon an element, for instance a copy carrier 2, the exposed wet surface thereof has to be dried. A pair of comb-shaped electrodes preferably made of steel, the pointed teeth of which are directed toward, but out of contact, with the exposed surface of the element 2 on the support plate 1 are arranged extending parallel to each other and substantially normal to the side edges of the support plate 1. The electrodes 5 are carried at opposite ends by carriage means 3 for movement in a direction substantially normal to the elongation of the comb-shaped electrodes 5 relative to the support plate, as indicated by the double-headed arrow 4. The support plate 1 is preferably provided along the side edges thereof with ledges l for guiding the carriage 3 in the aforementioned direction. Means,schematically indicated,are further provided to apply to the support plate and the comb-shaped electrodes 5 a potential difference U in the order of 4 to 8 kV. Of course, the carriage 3 has to be insulated from the support plate by providing the carrier for instance with rubber rollers. When such a potential difference is applied to the support plate 1 and the electrodes 5, and electrical field will be produced and the resulting field intensity at the points of the electrodes will be so great to ionize the air between electrodes and the exposed surface of the copy carrier 2 to thus produce gas ions emanating at high speed from the points of the electrode and a resulting gas-ion and air stream directed to the exposed surface of the copy carrier which will drive a liquid film on this surface off the latter during relative movement of the electrode and the carrier. The support plate 1 is preferably provided with a groove la extending around a copy carrier on the surface of the support plate for receiving the liquid pushed off the exposed surface of the copy carrier, and the aforementioned groove 1a preferably is connected to a container, not shown, for receiving the pushed off liquid.

FIG. 2 shows a second embodiment similar to the embodiment described above in connection with FIG. 1 and the main difference between the construction shown in FIG. 1 and that shown in FIG. 2 is that the comb-shaped electrodes 5' are in this embodiment substantially V-shaped and arranged in a plane substantially parallel to the exposed wet surface. The apex of the V-shaped electrodes 5' is arranged in such a man ner that during relative movement of the electrodes 5 and the support plate 1 with the copy carrier 2 thereon a wet film on the exposed carrier surface will be displaced toward the'side edges of the copy carrier. In other words, when the electrodes 5 are mounted on a carriage 3, which during its working stroke moves in the direction 40, the apex of the V-shaped electrodes 5 will lead in the direction of movement of the electrodes 5' relative to the copy carrier 2. On the other hand, if the electrodes are maintained stationarily,

while the support plate 1 with the copy carrier 2 thereon is moved in direction of the arrow 4b, the apex of the V-shaped electrodes will trail in direction of this movement.

FIG. 3 schematically illustrates a third embodiment in which the electrode means 6 is constituted by an elongated small-diameter cylinder, from the peripheral surface thereof a plurality of pointed elements project in substantially radial direction. The pointed elements are preferably arranged in rows circumferentially displaced about the peripheral surface of the cylinder.

Drive means are provided for rotating the cylindrical electrode 6 about its axis, and such drive means are shown in FIG. 3 as an electromotor 7 connected to the electrode for rotating the latter about its axis. For simplification reason, the support for the electrode and the electromotor connected thereto is not shown in the drawing, and these two members may be supported on a carriage 3 similar to that shown in FIG. 3 so that the electrode 6 and the drive motor 7 and the support plate 1 may be moved relative to each other in the direction as indicated by the double-headed arrow 4. The drive motor 7 is preferably reversible so that during movement of the electrode 6 toward the rear end of the support plate 1, as viewed in FIG. 3, the electrode 6 may be rotated about its axis in the direction of the arrow 6', whereas during movement of the electrode toward the front end of the support plate the electrode may be rotated in the opposite direction, to drive thereby a liquid film on the exposed wet surface of the copy carrier 2 ahead of the rotating electrode toward the respective end edge of the copy carrier 2. Of course, it is also possible to arrange the electrode and the motor 7 on a fixed support and to move the support plate 1 with the copy carrier thereon relative to the electrode in the direction as indicated by the double-headed arrow 4.

At pointed ends of the electrodes are in all'embodiments discussed above spaced a distance of about 10 to 12 mm from the exposed surface of the copy carrier 2.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of apparatus for drying wet surfaces differing from the types described above.

While the invention has been illustrated and de scribed as embodied in an apparatus for drying the exposed wet surface of a copy carrier or the like, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. Thus, for instance, the electrodes '5 as shown in FIG. 1 or the rotating electrode 6 illustrated in FIG. 3 may also be arranged inclined at an angle of less than to the direction of movement of the electrode relative to the support plate. It is further understood that not only surfaces of a photo carrier but also other surfaces may be dried with the apparatus according to the present invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

I claim:

1. A method of drying surfaces, especially the wet surface of an electrographic or dielectric copy carrier, comprising the steps of moving elongated electrode means, having a plurality of closely adjacent pointed elements, the points of which are closely adjacent but out of contact with the wet surface, and the wet surface relative to each other in a direction transverse to the elongation of said electrode means; and applying during such movement a potential difference to said electrode means and said surface to thus produce gas ions emanating at high speed from said electrode means, resulting in a gas-ion and air stream direct to said surface so as to push a liquid film on said wet surface off the latter during the relative movement of said electrode means and said surface.

' 2. A method as defined in claim 1, wherein said potential difference is in the order of 4-8 kV.

3. Apparatus for drying wet surfaces of elements, especially surfaces of an electrophotographic or dielectric copy carrier, comprising, in combination, support means having a surface for supporting an element with the wet surface thereof exposed; elongated electrode means having a plurality of closely adjacent pointed elements, the points of which are closely adjacent but out of contact with the exposed wet surface of an element on said support means, said support means and said electrode means being arranged for movement with respect to each other in a direction transverse to the elongation of said electrode means; and means for applying a potential difference to said electrode means and said support means and the element thereon.

4. An apparatus as defined in claim 3, wherein said support means is stationarily arranged, and including carriage means mounting said electrode means for movement in said transverse direction, and guide means on said support means for guiding said carriage during its movement relative to said support means.

5. Apparatus as defined in claim 3, wherein said pointed elements are constituted by teeth of a combshaped electrode.

6. Apparatus as defined in claim 4, wherein said pointed elements are constituted by teeth of a combshaped electrode, and wherein two such comb-shaped electrodes are arranged parallel to each other on said carriage.

7. Apparatus as defined in claim 3, wherein said elongated electrode means is V-shaped and located in a plane substantially parallel to said surface of said support means, with the apex of said V-shaped electrode means located between side edges of an element on said support means, said apex being arranged in such a manner that during relative movement of said electrode means and said support means with said element thereon, a wet film on said exposed surface will be displaced toward said side edges of said element.

8. Apparatus as defined in claim 7, wherein said support means has opposite ends and is arranged stationarily, and including carriage means mounting said V- shaped electrode means movable during a working stroke from one to the opposite end of said support means with the apex of said V-shaped electrode means leading during the movement of said carriage along said working stroke.

9. Apparatus as defined in claim 3, wherein said electrode means comprise an elongated cylinder and a plurality of pointed elements projecting closely arranged to each other in substantially radial direction from the peripheral surface of said cylinder, and including means for rotating said cylinder about its axis during relative movement of said electrode means and said element in a direction transverse to said axis. 

1. A method of drying surfaces, especially the wet surface of an electrographic or dielectric copy carrier, comprising the steps of moving elongated electrode means, having a plurality of closely adjacent pointed elements, the points of which are closely adjacent but out of contact with the wet surface, and the wet surface relative to each other in a direction transverse to the elongation of said electrode means; and applying during such movement a potential difference to said electrode means and said surface to thus produce gas ions emanating at high speed from said electrode means, resulting in a gas-ion and air stream direct to said surface so as to push a liquid film on said wet surface off the latter during the relative movement of said electrode means and said surface.
 2. A method as defined in claim 1, wherein said potential difference is in the order of 4-8 kV.
 3. Apparatus for drying wet surfaces of elements, especially surfaces of an electrophotographic or dielectric copy carrier, comprising, in combination, support means having a surface for supporting an element with the wet surface thereof exposed; elongated electrode means having a plurality of closely adjacent pointed elements, the points of which are closely adjacent but out of contact with the exposed wet surface of an element on said support means, said support means and said electrode means being arranged for movement with respect to each other in a direction transverse to the elongation of said electrode means; and means for applying a potential difference to said electrode means and said support means and the element thereon.
 4. An apparatus as defined in claim 3, wherein said support means iS stationarily arranged, and including carriage means mounting said electrode means for movement in said transverse direction, and guide means on said support means for guiding said carriage during its movement relative to said support means.
 5. Apparatus as defined in claim 3, wherein said pointed elements are constituted by teeth of a comb-shaped electrode.
 6. Apparatus as defined in claim 4, wherein said pointed elements are constituted by teeth of a comb-shaped electrode, and wherein two such comb-shaped electrodes are arranged parallel to each other on said carriage.
 7. Apparatus as defined in claim 3, wherein said elongated electrode means is V-shaped and located in a plane substantially parallel to said surface of said support means, with the apex of said V-shaped electrode means located between side edges of an element on said support means, said apex being arranged in such a manner that during relative movement of said electrode means and said support means with said element thereon, a wet film on said exposed surface will be displaced toward said side edges of said element.
 8. Apparatus as defined in claim 7, wherein said support means has opposite ends and is arranged stationarily, and including carriage means mounting said V-shaped electrode means movable during a working stroke from one to the opposite end of said support means with the apex of said V-shaped electrode means leading during the movement of said carriage along said working stroke.
 9. Apparatus as defined in claim 3, wherein said electrode means comprise an elongated cylinder and a plurality of pointed elements projecting closely arranged to each other in substantially radial direction from the peripheral surface of said cylinder, and including means for rotating said cylinder about its axis during relative movement of said electrode means and said element in a direction transverse to said axis. 